Feature Request: Add launcher for onscreen keyboard to lock screen.

[fonetek]

I have Manjaro Mate installed on a cheap 2 in 1. Mate Desktop works surprisingly well on a touchscreen device. I use Onboard for the on screen keyboard. There is an option to open keyboard on login screen, but not lock screen. Onboard also has an option to open on lock screen, but it doesn't work on Manjaro Mate or Ubuntu Mate. I can click on switch user as a work around, because it brings up login screen, but it's not ideal. This is the last issue I have stopping me from having a perfect setup.

[pokaalinkanssayohon]

I would need this same feature in Linux Mint with Mate Desktop.